Repairing speakers Options

[haarp]

Hello.

I've been using Technics speakers for quite a while now. A few weeks ago, someone thought it would be a good idea to prove a point by ramming an axe into their backside. That's no joke, he really did it.
Well, I have a gaping hole in both of them now, and they sound terrible. I have some kind of reverb effect in them, and Bass gets them to vibrate audibly.




I'm pretty sure I have to replace the backplate, aswell as the tube. Does anyone have experience with that? Is it possible? Where do I get the materials?

Help is appreciated

[JensRex]

The backside is easy enough to repair, provided you have a minimum of skill with with a saw. Just cut an MDF board to match the broken one.

The tubes... not so much.

[haarp]

The backside is easy enough to repair, provided you have a minimum of skill with with a saw. Just cut an MDF board to match the broken one.

Mhh, yes, sawing it to size shouldn't be hard. But how do i get the old one out and insert the new one? It's inserted into a groove, so I probably need to dissasemble the whole speaker. I fear that they're glued together...

The tubes... not so much.

Can't I just get new tubes, drill/saw a big hole into the backplate and mount them there?

[JensRex]

Glue might be a problem.

What I would probably do... saw away the back-plate, without disassembling the rest of the speaker cabinet (you can take out the drivers from the front, probably, to protect them from sawdust etc). Fabricate your new backplate. Using sticks of wood, make a rim inside the speaker to glue/screw the new backplate onto.

The tube isn't a problem, provided you can find a replacement. Alternatively, depending on your access to a suitable workshop, you can probably fabricate new ones from pipe.

[honestguv]

I'm pretty sure I have to replace the backplate, aswell as the tube. Does anyone have experience with that? Is it possible? Where do I get the materials?

Help is appreciated

Having looked up the model on google I saw one pair for GBP 19 + postage on ebay and another pair for GBP 20 on a site in London. It is likely to be cheaper to simply buy another pair second hand and use your current ones for spares when someone hammers the front rather than the back.

If you want to repair then I would suggest simply gluing a piece of wood over the holes. For the speaker in the upper photo this should be as good as new so long as there is an airtight seal. For the speaker in the lower one you will have a differently shaped exit hole in the port which should make no effective difference to the mass of fluid moving in and out the port but you might get a bit of flow noise with deep bass.

[hödyr]

Have a look at www.madisound.com or www.partsexpress.com for bassreflex tubes. You don't have to buy one that is exactly the same (also that would be the easiest solution ), you just have to make sure the frequency the port is set to is the same, that can be calculated.
I would just glue some MDF over the holes and probably move the destoryed port some inches down, it shouldn't make that much of a difference.

[haarp]

Thanks for the answers so far!

I'm pretty sure I have to replace the backplate, aswell as the tube. Does anyone have experience with that? Is it possible? Where do I get the materials?

Help is appreciated

Having looked up the model on google I saw one pair for GBP 19 + postage on ebay and another pair for GBP 20 on a site in London. It is likely to be cheaper to simply buy another pair second hand and use your current ones for spares when someone hammers the front rather than the back.

Nah. I'd rather repair them instead of buying new ones. I'm aiming to blow as little money as possible on this.

If you want to repair then I would suggest simply gluing a piece of wood over the holes. For the speaker in the upper photo this should be as good as new so long as there is an airtight seal. For the speaker in the lower one you will have a differently shaped exit hole in the port which should make no effective difference to the mass of fluid moving in and out the port but you might get a bit of flow noise with deep bass.

Have a look at www.madisound.com or www.partsexpress.com for bassreflex tubes. You don't have to buy one that is exactly the same (also that would be the easiest solution ), you just have to make sure the frequency the port is set to is the same, that can be calculated.
I would just glue some MDF over the holes and probably move the destoryed port some inches down, it shouldn't make that much of a difference.

Gluing stuff over the holes doesn't really sound promising. Better replace the whole backplate. In order to do that, I would need to disassemble the box. How to get rid of the glue? Brute Force? Some chemical cocktail that dissolves it?

Oh, I also forgot to mention that I would need a German parts dealer Already found one for the tubes, but not for MDF

btw, while I'm on it, I also heard there's some kind of fabric that you stuff inside your box. Is that any useful?

This post has been edited by haarp: Aug 25 2008, 17:42

[Sunhillow]

Hi

you might cut the holes to a more rectangular shape and glue a piece of chipboard or MDF into the hole.
To fill the gaps, a mix of sawdust and wood glue or sawdust and resin+hardener. Wood glue has the disadvantage to be humid and thus macerating chipboard a bit before it gets dry. But in your case this would not be too bad

btw, did you give the guy who produced the holes a powerful kick in the ass? What an idiot...

edit:
fabric inside the box helps to control resonances. Now as you mention it, I notice the inside of your speakers is empty
But as your speakers are vented it would be better to just apply acoustic foam to the side and rear walls

you can get MDF from Obi, Bauhaus, Hornbach etc. They will cut it to the dimensions you need

This post has been edited by Sunhillow: Aug 25 2008, 18:20

[Soap]

Gluing stuff over the holes doesn't really sound promising. Better replace the whole backplate.

Gluing a new board over the back is the simplest and cheapest option (assuming you have no saw) ASSuming the existing backplate is thin enough that you are not causing a significant increase in the enclosure volume. That being said I think you are missing the best answer, which is JensRex's suggestion to cut the back out and glue interior brackets in place to attach a new backplate.

How to get rid of the glue? Brute Force? Some chemical cocktail that dissolves it?

IF the enclosure's joints are glued (and not stapled) you're SOL. The glue @ the joint is likely stronger than the glue holding the wheat-straw together. Again, JensRex's idea is the best IMHO.

Oh, I also forgot to mention that I would need a German parts dealer Already found one for the tubes, but not for MDF

You don't need to use MDF, just about any board material will work. A quick stroll on trash day will provide plenty of suitable material.

[Livy]

I've been using Technics speakers for quite a while now...
Well, I have a gaping hole in both of them now, and they sound terrible...

They sound terrible now? Are you sure you really want to spend any money at all fixing these? You likely could buy used speakers for much less than the cost of a repair and probably get ones that are better sonically. Look on eBay...

My opinion is that you should put a fork in these. They're done.

[JensRex]

My opinion is that you should put a fork in these. They're done.

On second thought, maybe his axe wielding friend was doing him a favor.

[haarp]

Gluing stuff over the holes doesn't really sound promising. Better replace the whole backplate.

Gluing a new board over the back is the simplest and cheapest option (assuming you have no saw) ASSuming the existing backplate is thin enough that you are not causing a significant increase in the enclosure volume. That being said I think you are missing the best answer, which is JensRex's suggestion to cut the back out and glue interior brackets in place to attach a new backplate.

How to get rid of the glue? Brute Force? Some chemical cocktail that dissolves it?

IF the enclosure's joints are glued (and not stapled) you're SOL. The glue @ the joint is likely stronger than the glue holding the wheat-straw together. Again, JensRex's idea is the best IMHO.

Oh, I also forgot to mention that I would need a German parts dealer Already found one for the tubes, but not for MDF

You don't need to use MDF, just about any board material will work. A quick stroll on trash day will provide plenty of suitable material.

Alright. So it's the best idea to just rip the current backplate out completely and replace it. How about gluing the new plate directly to the back of the frame? This would increase the volume by just 0.6 liters. I have no idea if that makes any difference

I've been using Technics speakers for quite a while now...
Well, I have a gaping hole in both of them now, and they sound terrible...

They sound terrible now? Are you sure you really want to spend any money at all fixing these? You likely could buy used speakers for much less than the cost of a repair and probably get ones that are better sonically. Look on eBay...

My opinion is that you should put a fork in these. They're done.

Are they that bad? Well, at least they were a lot better than the cheapo active speaker set that I used before.
I don't really know any reasonably priced speakers with good quality and a maximum width of 24 cm. Can you recommend any? Are there any good review sites? I would need 4 of them, plus a center speaker (I don't really like those sets with subwoofer and small satellites. IMO, the satellites should be able to deliver the low frequencies on their own)

Thank you all for your help so far!

This post has been edited by haarp: Aug 25 2008, 21:16

[weaker]

Have a look at the nuBox series from Nubert.
They are not amongst the cheapest ones but deliver outstanding quality considering the price. And as even the smallest models use 19mm/38mm MDF your friend would have a harder time to axe them :-)
If 24,5 cm width is still acceptable I highly recommend the nuBox 381.
If you seek more info about them, look on their nuForum or consider the toll-free hotline. Their service is usually truly exceptional.

Disclaimer: I'm not affiliated with them in any way but am just a happy customer.

This post has been edited by weaker: Aug 25 2008, 23:32

[haarp]

Have a look at the nuBox series from Nubert.
They are not amongst the cheapest ones but deliver outstanding quality considering the price. And as even the smallest models use 19mm/38mm MDF your friend would have a harder time to axe them :-)
If 24,5 cm width is still acceptable I highly recommend the nuBox 381.
If you seek more info about them, look on their nuForum or consider the toll-free hotline. Their service is usually truly exceptional.

Disclaimer: I'm not affiliated with them in any way but am just a happy customer.

Almost 200 EUR a piece?! Sorry, That's a bit too much. That would almost be OK for a complete set (4 speaker + center). So that probably only leaves second hand...

This post has been edited by haarp: Aug 25 2008, 23:54